A buddy of mine has a 05 brute 750 its been running greatfor the past month with the 2" snorkels he put on did not have to jet or adjust mix screws. Then he put on a HMF slip on a couple of days ago, ran great with out putting the 155/165 jets in that HMF sent the first time we went riding, then yesterday he starts it to go riding and its now sputtering and backfiring like crazy. so then we went ahead and put in the jets in (155f and 165r). we still cant get it to run right from about half throttle to full its just sputtering and popping. we spent hours yesterday changing jets and messing with the mixture srews. What else can we try. Thanks in advance.